MATHEMATICS, SIMULATION AND MODELLING

Machines Environment update

20 February 2012

Cobham Technical Services

Cobham Technical Services has updated its design entry system that allows precision finite-element analysis (FEA) models of motors and generators to be created and solved in minutes. The two-dimensional (2D) version of the Machines Environment software has now been integrated with Cobham’s optimisation tool which automatically finds the optimal solution within a design space, even for multiple or competing design objectives.

Machines Environment is an application-specific extension to the well-known Opera electromagnetic simulation package. It provides a front-end to the simulator that speeds design entry by means of Wizard-style dialogue boxes. Users select the style of motor or generator they want to design from a library of all common types, including induction, brushless permanent magnet and switched reluctance motors, and synchronous motors or generators. Dialogue boxes then allow the user to enter parameters to define mechanical geometry, material properties and electrical data, automatically creating the FEA model.

Auto-optimisation tools usually require manual intervention if the globally optimal solution is to be found and the simulation times involved often make this impractical. Cobham's Optimizer tool 'intelligently' selects and manages multiple goal-seeking algorithms, including stochastic, descent, particle swarm and Kriging to eliminate the need for manual intervention. According to the company, setting up an Optimizer run from the Machines Environment has now been made as easy as the design entry process. Because most FEA simulations can take as little as a few seconds, the integrated software makes it feasible to thoroughly explore the design space. Thousands of simulations can typically be executed within hours, making the 'perfect solution' achievable for all users without expert assistance.

The 2D Machines Environment is now in its fourth generation and Cobham has developed an extensive library of rotating machine design styles and design components. However, if there are still any unusual features that need to be incorporated in designs, users also have open access to the scripts that generate the models and can modify them at will to automate proprietary motor and generator design concepts. A library of common material properties is also included in the design software. Again, if users employ any special materials, such as an unusual grade of steel for laminations, then a new menu item can be created within minutes. Cobham will also generate custom scripts for users on request.

A three-dimensional version of the Machines Environment is optionally available.